/**
* Copyright 2005 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.nutch.mapReduce.lib;
import java.io.IOException;
import java.util.StringTokenizer;
import org.apache.nutch.mapReduce.Mapper;
import org.apache.nutch.mapReduce.OutputCollector;
import org.apache.nutch.mapReduce.JobConf;
import org.apache.nutch.io.WritableComparable;
import org.apache.nutch.io.Writable;
import org.apache.nutch.io.LongWritable;
import org.apache.nutch.io.UTF8;
/** A {@link Mapper} that maps text values into <token,freq> pairs. Uses
* {@link StringTokenizer} to break text into tokens. */
public class TokenCountMapper implements Mapper {
public void configure(JobConf job) {}
public void map(WritableComparable key, Writable value,
OutputCollector output) throws IOException {
// get input text
long position = ((LongWritable)key).get(); // key is position in file
String text = ((UTF8)value).toString(); // value is line of text
// tokenize the value
StringTokenizer st = new StringTokenizer(text);
while (st.hasMoreTokens()) {
// output <token,1> pairs
output.collect(new UTF8(st.nextToken()), new LongWritable(1));
}
}
}